50 THE RELATION OF SPABROWS TO AGRICULTURE. 
without removing any of the ensheathing glumes. Gravel was fur- 
nished so thai the grinding power of the birds' gizzards might be 
facilitated, and after several hours 6 droppings were collected and 
examined. No whole seeds were found. There were, however, three 
oearly entire glumes and a pulverized mass of matter which under 
the microscope was seen to consist of fragments of broken glumes. 
Several days later about 500 crab-grass seeds were Ted to the same 
sparrows, no gravel being given at the time or during the interval 
between the two experiments. Twelve droppings were examined and 
the results were substantially the same as in the first experiment. 
Three different sparrows were then Un\ with about 1,000 crab-grass 
seeds and 20 droppings were collected. The result was the same. 
Not one of the 1,600 seeds was passed in a condition to germinate. 
Although these experiments are by no means conclusive, yet they 
strongly indicate thai the English sparrow, however harmful it may 
be in other ways, can not be held responsible for the occurrence of 
crab-grass in lawns. It is possible that the damage is due to the 
wind. Seeds of crab-grass are light and buoyant, and those attached 
to fallen spikes would he particularly likely to be carried along by 
the wind on gusty days. 
